Thickener comprising at least one cationic polymer

ABSTRACT

The present invention relates to a thickener comprising at least one cationic polymer and at least one activator. The at least one cationic polymer is preparable by polymerization of a) at least one water-soluble ethylenically unsaturated monomer comprising at least one cationic monomer, optionally at least one anionic monomer and/or optionally at least one nonionic monomer, b) at least one ethylenically unsaturated associative monomer, c) optionally at least one crosslinker, and d) optionally at least one chain transfer agent. The ratio of activator to cationic polymer is &gt;10 to 100 [% by weight/% by weight].

This patent application claims the benefit of U.S. provisionalapplication Ser. No. 61/558,444 filed on Nov. 11, 2011, incorporated inits entirety herein by reference.

The present invention relates to a thickener comprising at least onecationic polymer and at least one activator, wherein the ratio ofactivator to cationic polymer is >10:100 [% by weight/% by weight]. Thecationic polymer is preparable by polymerization of at least onewater-soluble, ethylenically unsaturated monomer and at least oneethylenically unsaturated associative monomer. The present inventionfurther relates to a process for preparing the inventive thickener andto surfactant-containing formulations comprising at least one thickener.The invention further provides for the use of the surfactant-containingformulations, for example as a softener or as a liquid washingcomposition, and to the use of the thickener, for example as a viscositymodifier.

WO 03/102043 relates to aqueous formulations comprising a cationicpolymer prepared from (i) a water-soluble, ethylenically unsaturatedmonomer or a monomer mixture comprising at least one cationic monomer,(ii) at least one crosslinker in an amount of more than 50 ppm based oncomponent (i), and (iii) at least one chain transfer agent. The aqueousformulations can be used as thickeners in domestic formulations.

WO 2009/019225 relates to an aqueous dispersion of an alkali-solublecopolymer, said dispersion being suitable as an associative thickener.The copolymer comprises polymerized units of a) at least oneethylenically unsaturated carboxylic acid, b) at least one nonionicethylenically unsaturated surfactant monomer, c) at least oneC₁-C₂-alkyl methacrylate and d) at least one C₂-C₄-alkyl acrylate, wherethe alkyl chain length averaged over the number of alkyl groups of thealkyl acrylate is 2.1 to 4.0. The associative thickeners can be preparedby emulsion polymerization. The associative thickeners are suitable foruse in washing and cleaning compositions.

Liquid Dispersion Polymer (LDP) compositions are disclosed in WO2005/097834. These LDP compositions comprise a hydrophilic,water-soluble or swellable polymer with a neutralization content ofabout 25 to about 100%, a nonaqueous carrier phase and an oil-in-watersurfactant. The hydrophilic, water-soluble or swellable, polymer ispreferably obtained by polymerization, for example of acrylic acid ormethacrylic acid. The LDP dispersions are suitable for production ofmicroparticulate thickeners, as used, for example, in aqueous or organiccompositions, especially in personal care or pharmaceuticalformulations.

WO 2010/078959 relates to cationic polymer thickeners consisting of acrosslinked water-swellable cationic polymer comprising at least onecationic monomer and optionally nonionic or anionic monomers, saidpolymer comprising less than 25% of water-soluble polymer chains, basedon the total weight of the polymer. The polymer also comprises acrosslinker in a concentration of 500 to 5000 ppm relative to thepolymer. The cationic polymer is prepared by inverse emulsionpolymerization.

WO 2010/079100 discloses fabric softener compositions comprisingpolymers according to WO 2010/078959.

US 2008/0312343 relates to inverse latex compositions and to the usethereof as a thickener, and/or emulsifier, for example for production ofcosmetic or pharmaceutical formulations. The inverse latex compositionscomprise at least 50 to 80% by weight of at least one linear, branchedor crosslinked organic polymer (P), at least 5 to 10% by weight of awater-in-oil-type emulsifier system, 5 to 45% by weight of at least oneoil and up to 5% water. The polymer P comprises uncharged monomers andoptionally cationic or anionic monomers. The inverse latex compositionmay optionally comprise up to 5% by weight of an oil-in-water-typeemulsifier system. The inverse latex compositions can be prepared byinverse emulsion polymerization.

EP-A 172 025 relates to a dispersion in a continuous liquid phase of apolymer, which is formed by polymerization of an ethylenicallyunsaturated monomer comprising a hydrophobic group of at least eightcarbon atoms and an ethylenically unsaturated monomer copolymerizabletherewith. The dispersion is stable and essentially anhydrous, andcomprises at least 40% by weight of polymer. In the polymerization, thecopolymerizable, ethylenically unsaturated monomers used may, forexample, be anionic monomers. The polymerization can be performed as aninverse emulsion polymerization.

EP-A 172 724 relates to polymers which are prepared by copolymerizationof a) an ethylenically unsaturated monomer comprising a hydrophobicgroup with at least eight carbon atoms and b) water-solubleethylenically unsaturated monomers. All monomers are soluble as amixture in water, and the polymer is prepared by inverse emulsionpolymerization. The polymer particles have a dry size of <4 μm. Themonomer components b) used may be anionic monomers such as acrylic acidin the form of the free acid or as a water-soluble salt, and nonionicmonomers such as acrylamide.

EP-A 172 723 relates to a process for flocculating a suspension using awater-soluble, essentially linear polymer with a “single point intrinsicviscosity” of >3. The polymer is a copolymer of two or moreethylenically unsaturated monomers comprising at least 0.5% by weight ofa monomer, comprising hydrophobic groups. The polymer may also be acationic polymer.

The problem underlying the present invention consists in the provisionof novel thickeners. The object is achieved by the inventive thickenerscomprising

i) at least one cationic polymer preparable by polymerization of

-   -   a) at least one water-soluble ethylenically unsaturated monomer        comprising at least one cationic monomer, optionally at least        one anionic monomer and/or optionally at least one nonionic        monomer,    -   b) at least one ethylenically unsaturated associative monomer,    -   c) optionally at least one crosslinker,    -   d) optionally at least one chain transfer agent,

ii) at least one activator,

where the ratio of activator to cationic polymer is >10 to 100 [% byweight/% by weight].

The inventive thickeners are notable in that they possess advantageousproperties with regard to deposition, shear dilution, stabilizationand/or viscosity (thickening). Deposition is understood to mean thedeposition of the active ingredients of, for example, a fabric softeneron a fiber during a washing operation. Applied to the present invention,this means that, for example, an inventive thickener comprising at leastone cationic polymer (active ingredient) is present in a fabric softenerand the fabric softener is used during or after the washing operation.The inventive thickeners promote this deposition of the activeingredient during or after the washing operation to a considerabledegree. Particularly good properties with regard to deposition can beachieved when cationic polymers based on at least one associativemonomer, a cationic monomer and a nonionic monomer such as acrylamideare used.

In the assessment of shear dilution, it is important that the thickeneror the corresponding fabric softener, in its ground state, is viscousand thick, while it is thin in the course of stirring. The improvedshear dilution has a positive effect on the lifetime and properties ofpumps in the production of the fabric softener, promotes convenientdosage for the consumer and promotes the residue-free use of the fabricsoftener, especially in the washing machines which possess an automaticdosage device. The inventive thickeners increase the stability of thethickener per se and that of the corresponding formulation. The settlingor creaming of particles is effectively prevented, irrespective ofwhether they are within the order of magnitude of nanometers,micrometers or millimeters. This is contributed to by the advantageousyield point of the inventive thickeners. They also have the advantagethat any redispersion required and thickening are achieved very rapidly.

Inventive thickeners in which a mixture of at least two activators ispresent, at least one activator having a high HLB value and at least oneactivator having a low HLB value, are associated with an additionaladvantage. The combination of such an activator mixture with cationicpolymers comprising at least one ethylenically unsaturated associativemonomer unit leads to spontaneous phase inversion (within seconds) inthe case of dilution of a thickener with water, without any requirementfor additional energy input, for example in the form of stirring.

Another advantage in the case of the inventive thickeners is that theratio of associative monomer to the overall polymer is relatively low.In the case of use of the thickener in surfactant-containingformulations, the effect of the associative monomers is optimal even inamounts of approx. 0.5% by weight (based on the polymer).

When the inventive thickeners are prepared by inverse emulsionpolymerization in which the temperature is kept constant at at least 40°C., good uniformity of distribution of the associative monomer units inthe cationic polymer can be observed. Especially in the case of smalluse amounts of, for example, 0.1 to 1% by weight of associativemonomers, this is advantageous with regard to the overall abovementionedrheological properties such as thickening, shear dilution,stabilization, and washing and rinse effects.

Embodiments of the present invention in which the cationic polymerspresent in the thickener are prepared using little or no crosslinker arelikewise associated with advantages. Due to the relatively high(water-)soluble components of the polymer, recoiling during a washingoperation is reduced. Consequently, the article to be washed, even afterrepeated washing operations, has clean fibers which have been freeeffectively of soil particles, such that no graying is detected. Onlyvery slight, if any, adhesion or redistribution of soilparticles/polymers on the washed articles is observed.

A further advantage of the inventive thickeners, in which the cationicpolymer is obtained by inverse emulsion polymerization at constanttemperature, is manifested in surfactant-containing formulations,especially in surfactant-containing acidic formulations, because a highthickening performance and/or marked shear dilution are achieved inthese formulations even at low thickener concentrations (<1% by weight).

In the context of the present invention, the definitions such asC₁-C₃₀-alkyl, as defined, for example, below for the R₄ radical informula (II), mean that this substituent (radical) is an alkyl radicalhaving a carbon atom number from 1 to 30. The alkyl radical may beeither linear or branched and optionally cyclic. Alkyl radicals whichhave both a cyclic and a linear component are likewise covered by thisdefinition. The same also applies to other alkyl radicals, for example aC₁-C₄-alkyl radical or a C₁₆-C₂₂-alkyl radical. The alkyl radicals mayoptionally also be mono- or polysubstituted by functional groups such asamino, quaternary ammonium, hydroxyl, halogen, aryl or heteroaryl.Unless stated otherwise, the alkyl radicals preferably do not have anyfunctional groups as substituents. Examples of alkyl radicals aremethyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, 2-ethylhexyl,tert-butyl (tert-Bu/t-Bu), cyclohexyl, octyl, stearyl or behenyl.

The present invention is specified further hereinafter.

The inventive thickener comprises, as component i), at least onecationic polymer. The cationic polymer is preparable by polymerizationof the following components a) and b), and optionally c) and d).

The component a) used is at least one water-soluble, ethylenicallyunsaturated monomer comprising at least one cationic monomer, optionallyat least one anionic monomer and/or optionally at least one nonionicmonomer. Cationic monomers as such, any anionic monomers present assuch, and any nonionic monomers present as such are known to thoseskilled in the art.

The cationic monomer according to component a) is preferably selectedfrom a compound of the formula (II)

where

R₁ is H or C₁-C₄-alkyl,

R₂ is H or methyl,

R₃ is C₁-C₄-alkyl,

R₄, R₅ and R₆ are each independently H or C₁-C₃₀-alkyl,

X is —O— or —NH— and

Y is Cl; Br; I; hydrogensulfate or methosulfate.

Particularly preferred cationic monomers are 2-trimethylammonioethylacrylate chloride (TMAEC) or 2-trimethylammonioethyl methacrylatechloride (TMAEMC). TMAEC is also referred to as quaternizeddimethylaminoethyl acrylate (DMAEA, MeClq) and TMAEMC as quaternizeddimethylaminoethyl methacrylate (DMAEMA, MeClq).

In one embodiment of the present invention, it is preferred that, in thecationic monomer of the formula (II),

i) R₁ and R₂ are each H or

ii) R₁ is H and R₂ is CH₃.

Any anionic monomer present in component a) is preferably selected fromacrylic acid, methacrylic acid, itaconic acid, maleic acid or a saltthereof; the anionic monomer is especially sodium acrylate. Whencomponent a) comprises at least one anionic monomer, it is present(based on component a)) preferably to an extent of 0.5 to 20% by weight.

Component a) may optionally comprise at least one nonionic monomer.Apart from the nitrogen-containing monomers described below, for examplethe compounds of the formula (III), esters of the above-describedanionic monomers are also suitable as nonionic monomers. Such nonionicmonomers are preferably the methyl or ethyl esters of acrylic acid ormethacrylic acid, such as ethyl acrylate or methyl acrylate.Additionally preferred are the corresponding dimethylamino-substitutedesters such as dimethylaminoethyl(meth)acrylate.

Preferably, the nonionic monomer according to component a) in thecationic polymer is selected from N-vinylpyrrolidone, N-vinylimidazole,or a compound of the formula (III)

where

R₇ is H or C₁-C₄-alkyl,

R₈ is H or methyl, and

R₉ and R₁₀ are each independently H or C₁-C₃₀-alkyl,

The nonionic monomer is more preferably acrylamide, methacrylamide ordialkylaminoacrylamide. When component a) comprises at least onenonionic monomer, it is preferably present to an extent of 0.5 to 70% byweight.

In a preferred embodiment of the present invention, component a) in thecationic polymer comprises 30 to 99.5% by weight of at least onecationic monomer and 0.5 to 70% by weight of at least one nonionicmonomer. In a further preferred embodiment of the present invention,component a) comprises 100% by weight of at least one cationic monomer.

Component b) used in the polymerization to prepare the cationic polymeris at least one ethylenically unsaturated associative monomer.Associative monomers as such are known to those skilled in the art.Suitable associative monomers are described, for example, in WO2009/019225. Associative monomers are also described as surfactantmonomers.

Preferably, the ethylenically unsaturated associative monomer accordingto component b) in the cationic polymer is selected from a compound ofthe formula (I)R—O—(CH₂—CHR′—O)_(n)—CO—CR″═CH₂  (I)

where

R is C₆-C₅₀-alkyl, preferably C₈-C₃₀-alkyl, especially C₁₆-C₂₂-alkyl,

R′ is H or C₁-C₄-alkyl, preferably H,

R″ is H or methyl,

n is an integer from 0 to 100, preferably 3 to 50, especially 25.

More preferably, component b) used is a compound of the formula (I) inwhich

R is C₁₆-C₂₂-alkyl,

R′ is H,

R″ is H or methyl and

n is 25.

Compounds of the formula (I) are commercially available in solution, forexample under the Plex 6954 O name from Evonik Röhm GmbH. These aremethacrylates of fatty alcohol ethoxylates. A suitable fatty alcoholethoxylate is, for example, the commercially available Lutensol® AT 25(BASF SE, Ludwigshafen, Germany).

The R radical in the compounds of the formula (I) may also be present asa mixture of radicals with different chain lengths, such as C₁₆ and C₁₈.One example thereof is C₁₆-C₁₈-fatty alcohol-(ethylene glycol)₂₅-ethermethacrylate, where both C₁₆ and C₁₈ fatty alcohol radicals (innon-negligible amounts) are present as a mixture. In contrast, forexample, in the compounds (of the formula (I)) behenyl-25 methacrylateand cetyl-25 methacrylate, the particular R radical is not present as amixture but as a C₂₂ or C₁₆ chain. Other chain lengths occur only in theform of impurities. The number “25” in these compounds of the formula(I) represents the size of the variables n.

In the preparation of the cationic polymer by polymerization, at leastone crosslinker may optionally be present as component c). Suitablecrosslinkers are known to those skilled in the art. Preferably, thecrosslinker according to component c) in the cationic polymer isselected from divinylbenzene; tetraallylammonium chloride; allylacrylates; allyl methacrylates; diacrylates and dimethacrylates ofglycols or polyglycols; butadiene; 1,7-octadiene, allylacrylamides orallylmethacrylamides; bisacrylamido acetic acid;N,N′-methylenebisacrylamide, or polyol polyallyl ethers such aspolyallyl sucrose or pentaerythritol triallyl ether. Additionallysuitable as a preferred crosslinker is dialkyldimethylammonium chloride.

It is additionally possible, in the preparation of the cationic polymerby polymerization, to use at least one chain transfer agent as componentd). Suitable chain transfer agents are known to those skilled in theart. Preferred chain transfer agents according to component d) areselected from mercaptan, lactic acid, formic acid, isopropanol orhypophosphites.

Suitable polymerization processes for preparation of the cationicpolymer or the inventive thickener comprising at least one cationicpolymer, and any additives or assistants used in the polymerization orthe thickener preparation process, are defined in detail in the textbelow.

Preferably, the inventive thickener comprises at least one cationicpolymer preparable by polymerization of

-   a) 20 to 99.99% by weight, preferably 95 to 99.95% by weight (based    on the polymer), of at least one water-soluble ethylenically    unsaturated monomer comprising at least one cationic monomer, and    optionally at least one anionic monomer and/or at least one nonionic    monomer,-   b) 0.01 to 80% by weight, preferably 0.05 to 5% by weight, more    preferably 0.1 to 1% by weight (based on the polymer), of at least    one ethylenically unsaturated associative monomer,-   c) 0 to 0.3% by weight, preferably 0.01 to 0.1% by weight (based on    the polymer), of optionally at least one crosslinker,-   d) 0 to 0.3% by weight, preferably 0.01 to 0.1% by weight (based on    the polymer), of optionally at least one chain transfer agent.

In a further embodiment of the present invention, the water-solublecomponents of the cationic polymer are more than 25% by weight (based onthe total weight of the cationic polymer), especially when little or nocrosslinker is used in addition to the associative monomer. Preferablymore than 40% by weight, especially 70 to 100% by weight, of thecationic polymer is soluble in water. The solubility of the cationicpolymer is determined by methods known to those skilled in the art, byadmixing the cationic polymer present in the inventive thickener with adefined amount of water (see, for example, EP-A 343 840 or preferablythe determination method of the sedimentation coefficient in the unit ofsvedberg (sved) according to P. Schuck, ‘Size-distribution analysis ofmacromolecules by sedimentation velocity ultracentrifugation and Lammequation modeling’, Biophysical Journal 78, (3) (2000), 1606-1619).

Preferably, in this embodiment, the proportion of crosslinker (componentc)) used in the polymerization of the cationic polymer is <1% by weight(based on the total amount of components a) to d)). More preferably, nocrosslinker is used in the polymerization of the cationic polymer.

The inventive thickener further comprises, as components ii), at leastone activator. Activators as such are known in principle to thoseskilled in the art.

Suitable activators are preferably surfactants, for example anionic,nonionic, cationic and/or amphoteric surfactants, which are disclosed,for example, in WO 2009/019225. Preference is given to using anionicand/or nonionic surfactants.

The nonionic surfactants used are preferably fatty alcohol alkoxylates.Fatty alcohol alkoxylates are also referred to as polyalkylene glycolethers. Preferred fatty alcohol alkoxylates are alkoxylated,advantageously ethoxylated, especially primary alcohols havingpreferably 8 to 18 carbon atoms and an average of 1 to 12 mol ofethylene oxide (EO) per mole of alcohol, in which the alcohol radicalmay be linear or branched, preferably 2-methyl-branched, or may compriselinear and methyl-branched radicals in a mixture, as typically presentin oxoalcohol radicals. Especially preferred are, however, alcoholethoxylates with linear radicals formed from alcohols of native ortechnical origin with 12 to 18 carton atoms, for example formed fromcoconut alcohol, palm alcohol, tallow fat alcohol or oleyl alcohol—ormixtures as derivable, for example, from castor oil—and an average of 2to 8 EO per mole of alcohol. The preferred ethoxylated alcohols include,for example, C₁₂-C₁₄-alcohols with 3 EO, 4 EO or 7 EO, C₉-C₁₁-alcoholwith 7 EO, C₁₃-C₁₅-alcohols with 3 EO, 5 EO, 7 EO or 8 EO,C₁₂-C₁₈-alcohols with 3 EO, 5 EO or 7 EO and mixtures thereof such asmixtures of C₁₂-C₁₄-alcohol with 3 EO and C₁₂-C₁₈-alcohol with 7 EO. Thedegrees of ethoxylation reported are statistical averages which may bean integer or a fraction for a specific product. Preferred alcoholethoxylates have a narrow homolog distribution (narrow rangeethoxylates, NRE). In addition to these nonionic surfactants, it is alsopossible to use fatty alcohols with more than 12 EO. Examples thereofare tallow fat alcohol with 14 EO, 25 EO, 30 EO or 40 EO. It is alsopossible to use nonionic surfactants comprising EO and PO groupstogether in a molecule. In this context, it is possible to use blockcopolymers with EO-PO block units or PO-EO block units, but alsoEO-PO-EO copolymers or PO-EO-PO copolymers. It will be appreciated thatit is also possible to use mixed-alkoxylation nonionic surfactants inwhich EO and PO units are not present in blocks but in randomdistribution. Such products are obtainable by simultaneous action ofethylene oxide and propylene oxide on fatty alcohols.

In addition, further nonionic surfactants used may also be alkylglycosides or alkyl polyglycosides. Alkyl glycosides or alkylpolyglycosides are generally understood by the person skilled in the artto mean compounds composed of at least one alkyl fragment and at leastone sugar or polysugar fragment. The alkyl fragments preferably derivefrom fatty alcohols having a carbon atom number of 12 to 22, and thesugar fractions preferably from glucose, sucrose or sorbitan.

For example, it is possible to use alkyl glycosides of the generalformula (1)R¹O(G)_(x)  (1)in which R¹ is a primary straight-chain or methyl-branched, especially2-methyl-branched, aliphatic radical having 8 to 22 and preferably 12 to18 carbon atoms, and G is a glycoside unit having 5 or 6 carbon atoms,preferably glucose. The degree of oligomerization x, which specifies thedistribution of monoglycosides and oligoglycosides, is any numberbetween 1 and 10; x is preferably 1.2 to 1.4.

A further class of nonionic surfactants used with preference, which areused either as the sole nonionic surfactant or in combination with othernonionic surfactants, is that of alkoxylated, preferably ethoxylated orethoxylated and propoxylated, fatty acid alkyl esters, preferably having1 to 4 carbon atoms in the alkyl chain, especially fatty acid methylesters, as described, for example, in Japanese patent application JP58/217598, or which are preferably prepared by the process described ininternational patent application WO-A-90/13533.

Nonionic surfactants of the amine oxide type may also be suitable, forexample N-cocoalkyl-N,N-dimethylamine oxide andN-tallowalkyl-N,N-dihydroxyethylamine oxide, and of the fatty acidalkanolamide type. The amount of these nonionic surfactants ispreferably not more than that of the ethoxylated fatty alcohols,especially not more than half thereof.

Further suitable surfactants are polyhydroxy fatty acid amides of theformula (2),

in which R²C(═O) is an aliphatic acyl radical having 6 to 22 carbonatoms, R³ is hydrogen, an alkyl or hydroxyalkyl radical having 1 to 4carbon atoms, and [Z] is a linear or branched polyhydroxyalkyl radicalhaving 3 to 10 carbon atoms and 3 to 10 hydroxyl groups. The polyhydroxyfatty acid amides are known substances, which can be obtained typicallyby reductive amination of a reducing sugar with ammonia, an alkylamineor an alkanolamine, and subsequent acylation with a fatty acid, a fattyacid alkyl ester or a fatty acid chloride.

The group of the polyhydroxy fatty acid amides also includes compoundsof the formula (3)

in which R⁴ is a linear or branched alkyl or alkenyl radical having 7 to12 carbon atoms, R⁵ is a linear, branched or cyclic alkylene radicalhaving 2 to 8 carbon atoms or an arylene radical having 6 to 8 carbonatoms, and R⁶ is a linear, branched or cyclic alkyl radical or an arylradical, or an oxyalkyl radical having 1 to 8 carbon atoms, preferencebeing given to C₁-C₄-alkyl or phenyl radicals, and [Z]¹ is a linearpolyhydroxyalkyl radical whose alkyl chain is substituted by at leasttwo hydroxyl groups, or alkoxylated, preferably ethoxylated orpropoxylated, derivatives of this radical. [Z]¹ is preferably obtainedby reductive amination of a sugar, for example glucose, fructose,maltose, lactose, galactose, mannose or xylose. The N-alkoxy- orN-aryloxy-substituted compounds can then be converted to the desiredpolyhydroxy fatty acid amides, for example, according to WO-A-95/07331by reaction with fatty acid methyl esters in the presence of an alkoxideas a catalyst.

The anionic surfactants used are, for example, those of the sulfonateand sulfate type. Useful surfactants of the sulfonate type includealkylbenzenesulfonates, preferably C₉-C₁₃-alkylbenzenesulfonates,olefinsulfonates, i.e. mixtures of alkene- and hydroxyalkanesulfonates,and disulfonates as obtained, for example, from C₁₂-C₁₈-monoolefins withterminal or internal double bonds by sulfonation with gaseous sulfurtrioxide and subsequent alkaline or acidic hydrolysis of the sulfonationproducts. Also suitable are alkanesulfonates, preferably secondaryalkanesulfonates, which are obtained, for example, from C₁₂-C₁₈-alkanesby sulfochlorination or sulfoxidation with subsequent hydrolysis orneutralization. Equally suitable are also the esters of α-sulfone fattyacids (ester sulfonates), for example the α-sulfonated methyl esters ofhydrogenated coconut fatty acids, palm kernel fatty acids or tallowfatty acids.

Further suitable anionic surfactants are sulfonated fatty acid glycerylesters. Fatty acid glyceryl esters are understood to mean the mono-, di-and triesters, and mixtures thereof as obtained in the preparation byesterification of a monoglycerol with 1 to 3 mol of fatty acid or in thetransesterification of triglycerides with 0.3 to 2 mol of glycerol.Preferred sulfonated fatty acid glyceryl esters are the sulfonationproducts of saturated fatty acids having 6 to 22 carbon atoms, forexample of caproic acid, caprylic acid, capric acid, myristic acid,lauric acid, palmitic acid, stearic acid or behenic acid.

Further suitable anionic surfactants are fatty alcohol sulfates, forexample alk(en)yl sulfates. Preferred alk(en)yl sulfates are the alkalimetal and especially the sodium salts of the sulfuric monoesters of theC₁₂-C₁₈ fatty alcohols, for example of coconut fatty alcohol, tallowfatty alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol orstearyl alcohol, or of the C₁₀-C₂₀ oxo alcohols and those monoesters ofsecondary alcohols of these chain lengths. Additionally preferred arealk(en)yl sulfates of the chain length mentioned which comprise asynthetic straight-chain alkyl radical produced on a petrochemicalbasis, which have analogous degradation behavior to the equivalentcompounds based on fatty-chemical raw materials. In the interests ofwashing technology, preference is given to the C₁₂-C₁₆-alkyl sulfatesand C₁₂-C₁₅-alkyl sulfates, and also C₁₄-C₁₅-alkyl sulfates. Suitableanionic surfactants are also 2,3-alkyl sulfates, which are prepared, forexample, according to U.S. Pat. No. 3,234,258 or U.S. Pat. No. 5,075,041and can be obtained as commercial products from Shell Oil Company underthe DAN® name.

Also suitable are the sulfuric monoesters of the straight-chain orbranched C₇-C₂₁-alcohols ethoxylated with 1 to 6 mol of ethylene oxide,such as 2-methyl-branched C₇-C₁₁ alcohols with an average of 3.5 mol ofethylene oxide (EO) or C₁₂-C₁₈-fatty alcohols with 1 to 4 EO.

Further suitable anionic surfactants are also the salts ofalkylsulfosuccinic acid, which are also referred to as sulfosuccinatesor as sulfosuccinic esters, and which are monoesters and/or diesters ofsulfosuccinic acid with alcohols, preferably fatty alcohols andespecially ethoxylated fatty alcohols. Preferred sulfosuccinatescomprise C₈-C₁₈-fatty alcohol radicals or mixtures thereof. Especiallypreferred sulfosuccinates comprise a fatty alcohol radical which derivesfrom ethoxylated fatty alcohols. Particular preference is given in turnto sulfosuccinates whose fatty alcohol radicals derive from ethoxylatedfatty alcohols with narrow homolog distribution. It is likewise alsopossible to use alk(en)ylsuccinic acid with preferably 8 to 18 carbonatoms in the alk(en)yl chain or salts thereof.

Further suitable anionic surfactants are alkyl carboxylates, for examplethe sodium salts of saturated or unsaturated fatty acids, where thealkyl radical of the alkyl carboxylate is preferably linear.

In the context of the present invention, the activator is preferablyselected from fatty alcohol alkoxylates, alkyl glycosides, alkylcarboxylates, alkylbenzenesulfonates, secondary alkanesulfonates andfatty alcohol sulfates, more preferably selected from fatty alcoholalkoxylates. One example of a preferred fatty alcohol alkoxylate isC₆-C₁₇(secondary)-poly(3-6)ethoxylate.

It is additionally preferred in the context of the present invention touse an activator which has a (relatively) high HLB(hydrophilic-lipophilic balance) value. The activator preferably has anHLB value of 7 to 18, more preferably of 8 to 15 and especiallypreferably of 9 to 13.

Activators with a high HLB value are preferably i) fatty alcoholalkoxylates formed from secondary alcohols or mixtures of alcoholshaving 12 to 18 carbon atoms and ethylene oxide or propylene oxide, andii) alkyl glycosides formed from sucrose and C₈ to C₂₂ fatty alcohols.Examples of such activators are the commercially available Synperonic87K from Croda GmbH, Herrenpfad-Süd 33, 41334 Nettetal, Germany;Croduret 40 or other ethoxylated hydrogenated castor oils (ricinus oils)such as Etocas 40 or Crodesta F110, all from Croda.

In a further embodiment of the present invention, it is preferred to usea mixture of at least two activators, at least one activator having ahigh HLB value and at least one activator a low HLB value. The activatorwith a high HLB value preferably has a HLB value of >12 to 20, and theactivator with a low HLB value preferably has an HLB value of 1 to 12.In this embodiment, the activator with a high HLB value and theactivator with a low HLB value may be present in any desired ratiosknown to those skilled in the art. Preferably, in the mixture, 20 to 50%by weight of activator with high HLB value and 50 to 80% by weight ofactivator with low HLB value are used. Additionally preferably, thisratio of activator with high HLB value to activator with low HLB valueis adjusted such that the overall HLB value is 7 to 18, more preferably8 to 15 and especially preferably 9 to 13.

In these mixtures of at least two activators, the activators with a highHLB value used are preferably alkyl glycosides or polyalkyl glycosidesor polyalkyl oligoethylene oxide glycoside based on sucrose or sorbitanand C₈ to C₂₂ fatty alcohols such as polyethylene glycol sorbitanmonostearate or polyoxyethylene sorbitan monostearate. Examples of suchactivators are the commercially available Crillet 1, Crillet 3 orCrodesta F160, all obtainable from Croda. The activators used with a lowHLB value are preferably alkyl glycosides formed from sucrose orsorbitan and C₈ to C₂₂ fatty alcohols or fatty acids, such as sorbitanlaurate or sorbitan stearate. Examples of such activators are thecommercially available Crill 1, Crill 3 or Crodesta F10 from Croda.

According to the invention, the ratio of activator to the cationicpolymer is >10:100 [% by weight/% by weight], preferably 10.5 to 50:100[% by weight/% by weight], more preferably 11.5 to 20:100 [% by weight/%by weight].

In the inventive thickeners, further components may be present inaddition to the cationic polymer and the activator. Suitable furthercomponents are defined in detail in the text which follows in thecontext of the preparation of the thickener and of the cationic polymer.Suitable further components may, for example, be oils and solvents.

In the inventive thickener, the cationic polymer may be presentdispersed in the oil phase, preferably as an inverse dispersion,water-in-oil dispersion, or as a dispersed anhydrous cationic polymer inoil.

The present invention further provides a process for preparing theinventive thickeners. Thickener preparation processes as such andprocesses for preparing a polymer are known to those skilled in the art.The polymer is preferably obtained by an emulsion polymerization,especially by an inverse emulsion polymerization. The polymer ispreferably first prepared and, after the polymerization, preferably byinverse emulsion polymerization, the activator is added to obtain thethickener.

The cationic polymer is preparable in various ways, preferably byemulsion polymerization, especially by inverse emulsion polymerization.Inverse emulsion polymerization is understood by the person skilled inthe art generally to mean polymerization processes according to thefollowing definition: the hydrophilic monomers are dispersed in ahydrophobic oil phase. The polymerization is effected directly in thishydrophilic monomer particle by addition of initiator.

In addition, it is preferred that, after the inverse emulsionpolymerization and before the addition of activator, at least a portionof water and at least a portion of the low-boiling constituents of theoil phase are distilled off, especially by means of LDP technology(Liquid Dispersion Polymer Technology). LDP technology as such is knownto those skilled in the art; it is described, for example, in WO2005/097834.

The information which follows, unless stated otherwise, applies to allkinds of emulsion polymerization, for example to emulsion polymerizationin water, which then constitutes the continuous phase, and especiallyalso to inverse emulsion polymerization in which the hydrophobic oilphase constitutes the continuous phase. A suitable polymerizationinitiator is used for the polymerization. Redox initiators and/orthermally activatable free-radical polymerization initiators arepreferred.

Suitable thermally activatable free-radical initiators or the oxidativecomponent of the redox initiator pair are in particular those of theperoxy and azo type. These include hydrogen peroxide, peracetic acid,t-butyl hydroperoxide, di-t-butyl peroxide, dibenzoyl peroxide, benzoylhydroperoxide, 2,4-dichlorobenzoyl peroxide,2,5-dimethyl-2,5-bis(hydroperoxy)hexane, perbenzoic acid, t-butylperoxypivalate, t-butyl peracetate, dilauroyl peroxide, dicapryloylperoxide, distearoyl peroxide, dibenzoyl peroxide, diisopropylperoxydicarbonate, didecyl peroxydicarbonate, dieicosylperoxydicarbonate, di-t-butyl perbenzoate, azobisisobutyronitrile,2,2′-azobis-2,4-dimethylvaleronitrile, ammonium persulfate, potassiumpersulfate, sodium persulfate and sodium perphosphate.

The persulfates (peroxodisulfates), especially sodium persulfate, aremost preferred. In the performance of the emulsion polymerization, theinitiator is used in a sufficient amount to initiate the polymerizationreaction. The initiator is typically used in an amount of about 0.01 to3% by weight, based on the total weight of the monomers used. The amountof initiator is preferably about 0.05 to 2% by weight and especially 0.1to 1% by weight, based on the total weight of the monomers used.

The emulsion polymerization is effected typically at 0° C. to 100° C. Itcan be performed either as a batch process or in the form of a feedprocess. In the feed method, at least a portion of the polymerizationinitiator and optionally a portion of the monomers are initially chargedand heated to polymerization temperature, and then the rest of thepolymerization mixture is supplied, typically over several separatefeeds, one or more of which comprise the monomers in pure or emulsifiedform, continuously or stepwise while maintaining the polymerization.Preference is given to supplying the monomer in the form of a monomeremulsion. In parallel to the monomer supply, further polymerizationinitiator can be metered in.

In preferred embodiments, the entire amount of initiator is initiallycharged, i.e. there is no further metering of initiator parallel to themonomer feed.

In a preferred embodiment, the thermally activatable free-radicalpolymerization initiator is therefore initially charged completely andthe monomer mixture, preferably in the form of a monomer emulsion, isfed in. Before the feeding of the monomer mixture is started, theinitial charge is brought to the activation temperature of the thermallyactivatable free-radical polymerization initiator or a highertemperature. The activation temperature is considered to be thetemperature at which at least half of the initiator has decomposed afterone hour.

In another preferred preparation method, the cationic polymer isobtained by polymerization of a monomer mixture in the presence of aredox initiator system. A redox initiator system comprises at least oneoxidizing agent component and at least one reducing agent component, inwhich case heavy metal ions are preferably additionally present as acatalyst in the reaction medium, for example salts of cerium, manganeseor iron(II).

Suitable oxidizing agent components are, for example, peroxides and/orhydroperoxides such as hydrogen peroxide, tert-butyl hydroperoxide,cumene hydroperoxide, pinane hydroperoxide, diisopropylphenylhydroperoxide, dicyclohexyl percarbonate, dibenzoyl peroxide, dilauroylperoxide and diacetyl peroxide. Hydrogen peroxide and tert-butylhydroperoxide are preferred.

Suitable reducing agent components are alkali metal sulfites, alkalimetal dithionites, alkali metal hyposulfites, sodium hydrogensulfite,Rongalit C (sodium formaldehydesulfoxylate), mono- and dihydroxyacetone,sugars (e.g. glucose or dextrose), ascorbic acid and salts thereof,acetone bisulfite adduct and/or an alkali metal salt ofhydroxymethanesufinic acid. Sodium hydrogensulfite or sodiummetabisulfite is preferred.

Suitable reducing agent components or catalysts are also iron(II) salts,for example iron(II) sulfate, tin(II) salts, for example tin(II)chloride, titanium(III) salts such as titanium(III) sulfate.

The amounts of oxidizing agent used are 0.001 to 5.0% by weight,preferably from 0.005 to 1.0% by weight and more preferably from 0.01 to0.5% by weight, based on the total weight of the monomers used. Reducingagents are used in amounts of 0.001 to 2.0% by weight, preferably of0.005 to 1.0% by weight and more preferably of 0.01 to 0.5% by weight,based on the total weight of the monomers used.

A particularly preferred redox initiator system is the sodiumperoxodisulfate/sodium hydrogensulfite system, for example 0.001 to 5.0%by weight of sodium peroxodisulfate and 0.001 to 2.0% by weight ofsodium hydrogensulfite, especially 0.005 to 1.0% by weight of sodiumperoxodisulfate and 0.005 to 1.0% by weight of sodium hydrogensulfite,more preferably 0.01 to 0.5% by weight of sodium peroxodisulfate and0.01 to 0.5% by weight of sodium hydrogensulfite.

A further particularly preferred redox initiator system is the t-butylhydroperoxide/hydrogen peroxide/ascorbic acid system, for example 0.001to 5.0% by weight of t-butyl hydroperoxide. 0.001 to 5.0% by weight ofhydrogen peroxide and 0.001 to 2.0% by weight of ascorbic acid,especially 0.005 to 1.0% by weight of t-butyl hydroperoxide, 0.005 to1.0% by weight of hydrogen peroxide and 0.005 to 1.0% by weight ofascorbic acid, more preferably 0.01 to 0.5% by weight of t-butylhydroperoxide, 0.01 to 0.5% by weight of hydrogen peroxide and 0.01 to0.5% by weight of ascorbic acid.

The cationic polymer is preferably prepared by inverse emulsionpolymerization, by first separately preparing an aqueous phase of thewater-soluble components and an oil phase. Thereafter, the two phasesare mixed with one another to obtain a water-in-oil dispersion. Themixture is polymerized by adding a redox initiator system; optionally,another, thermal initiator can subsequently be added or, if alreadypresent, thermally activated.

The aqueous phase comprises, for example, a chain transfer agent, acrosslinker, a cationic monomer and optionally an uncharged monomer, andalso the associative monomer, and optionally further components.Suitable further components are, for example, complexing agents forsalts such as pentasodium diethylenetriaminepentaacetic acid, orcompounds which can be used to adjust the pH, such as citric acid. Inaddition, an anionic monomer may optionally be present in the aqueousphase.

The oil phase preferably comprises an emulsifier, a stabilizer, ahigh-boiling oil, a low-boiling oil and/or optionally the associativemonomer. In addition, the oil phase may optionally comprise a nonionicmonomer.

Emulsifiers, stabilizers, low-boiling oils and high-boiling oils as suchare known to those skilled in the art. These compounds can be usedindividually or in the form of mixtures.

Typical emulsifiers are anionic emulsifiers, for example sodiumlaurylsulfate, sodium tridecyl ether sulfates, dioctylsulfosuccinatesodium salt and sodium salts of alkylaryl polyether sulfonates; andnonionic emulsifiers, for example alkylaryl polyether alcohols andethylene oxide-propylene oxide copolymers. Sorbitan trioleate islikewise suitable as an emulsifier.

Preferred emulsifiers have the following general formula:R—O—(CH₂—CHR′—O)_(n)—Xin which R is C₆-C₃₀-alkyl,R′ is hydrogen or methyl,X is hydrogen or SO₃M,M is hydrogen or one alkali metal, andn is an integer from 2 to 100.

Suitable stabilizers are described, for example, in EP-A 172 025 or EP-A172 724. Preferred stabilizers are copolymers of stearyl methacrylateand methacrylic acid.

Suitable high-boiling oils are, for example, 2-ethylhexyl stearate andhydroheated heavy naphtha, and suitable low-boiling oils are, forexample, dearomatized aliphatic hydrocarbons or mineral oils of lowviscosity.

In a preferred embodiment of the present invention, component b) (atleast one ethylenically unsaturated associative monomer) is added to theoil phase in the inverse emulsion polymerization.

In the inverse emulsion polymerization, the temperature can be keptconstant or else it can rise. The rise in the temperature can beperformed continuously or in stages. For example, the temperature canrise by 0.2 to 10° C. per minute during the polymerization, preferablyfrom 1 to 3° C. per minute. The temperature rise is controlled by therate of initiator addition. The starting temperature value may be 0 to30° C. preferably 10 to 20° C.

In another embodiment of the present invention, the temperature in theinverse emulsion polymerization is kept constant (cold method); thetemperature is 0 to 30° C., preferably 10 to 20° C. In a furtherembodiment of the present invention, the temperature is kept constantwithin a higher temperature range (hot method). The temperature in thepolymerization is 40 to 150° C., preferably 70 to 120° C.

In a particularly preferred embodiment of the present invention, thetemperature is kept constant during the inverse emulsion polymerization,the temperature being at least 40° C., preferably 50 to 90° C.

If, in the context of the present invention, the temperature is keptconstant in a polymerization, especially in an inverse emulsionpolymerization, this means that the temperature is kept at a constantvalue from the start of the polymerization. Variations of +/−5° C.,preferably +/−2° C. and especially +/−1° C. during the polymerizationprocess are considered to be a constant temperature (based on thedesired constant temperature value). The temperature is kept constantuntil the polymerization has ended, which is preferably the case after aconversion of more than 90% of the monomers used, more preferably morethan 95% by weight and especially preferably at full conversion (100% byweight). The temperature can be kept constant by removing the heat ofreaction which arises by cooling. The start of the polymerization isnormally the addition of the polymerization initiator, preferably theaddition of a redox initiator system. Normally, the system is firstheated to the desired temperature and a constant temperature is awaitedwhile stirring. Subsequently, the polymerization initiator is added, asa result of which the polymerization process commences. In oneembodiment of the present invention, the temperature is kept constant ata value above the melting point of the associative monomer used.

The present invention further provides surfactant-containing acidicformulations comprising at least one inventive thickener according tothe above definitions. The pH of the formulation is 1 to <7.

The present invention further provides surfactant-containing alkalineformulations comprising at least one inventive thickener according tothe above definitions. The pH of the formulation is 7 to 13.

The inventive surfactant-containing acidic or alkaline formulations maycomprise further ingredients known to those skilled in the art. Suitableingredients comprise one or more substances from the group of thebuilders, bleaches, bleach activators, enzymes, electrolytes, nonaqueoussolvents, pH modifiers, fragrances, perfume carriers, fluorescers, dyes,hydrotropes, foam inhibitors, silicone oils, antiredeposition agents,optical brighteners, graying inhibitors, antishrink agents, anticreaseagents, dye transfer inhibitors, active antimicrobial ingredients,germicides, fungicides, antioxidants, corrosion inhibitors, antistats,ironing aids, hydrophobizing and impregnating agents, swelling andantislip agents, and UV absorbers.

In one embodiment of the present invention, the surfactant-containingformulations, especially surfactant-containing acidic formulations,comprise less than 1% by weight of thickener (based on the overallformulation), the cationic polymer of the thickener being obtained byinverse emulsion polymerization at constant temperature. Preferably, theformulations comprise 0.1 to <1% by weight of thickener.

The present invention further provides for the use of an inventivesurfactant-containing acidic formulation in hair cosmetics, in hairstyling, as a shampoo, as a softener, as a conditioner, as a skin cream,as a shower gel, as a fabric softener for laundry, or as an acidicdetergent, preferably for toilets or baths.

The present invention further provides for the use of asurfactant-containing alkaline formulation as a liquid washingcomposition or as a machine or manual dishwashing detergent.

The present invention further provides for the use of the inventivethickener as a viscosity modifier, for optimization of shear dilution,as a thickening agent, for stabilization of suspended constituentshaving a size in the range from nanometers to millimeters and/or insurfactant-containing acidic or alkaline formulations.

In the description including the examples, the following abbreviationsare used:

Monomers

-   -   ACM acrylamide    -   AA acrylic acid    -   MAA methacrylic acid    -   NaAc sodium acrylate    -   TMAEC 2-trimethylammoniumethyl acrylate chloride    -   TMAEMC 2-trimethylammoniumethyl methacrylate chloride    -   BEM behenyl-25 methacrylate    -   MBA methylene-bis-acrylamide (crosslinker)    -   TAAC tetraallyl-ammonium chloride (crosslinker)    -   NaHP sodium hypophosphite (chain transfer agent)    -   C16EO25MAc C₁₆-C₁₈-fatty alcohol-(ethylene glycol)₂₅ ether        methacrylate

Others

-   -   pphm parts per hundred parts of monomers (based on components a)        and b))

The invention is illustrated hereinafter by the examples.

EXAMPLES Comparative Example C1

Synthesis of a thickener/polymer proceeding from cationic monomerswithout associative monomer, but with crosslinker and chain transferagent and rising polymerization temperature.

An aqueous phase of water-soluble components is prepared by mixing thefollowing components:

1.23 g (0.5 pphm) of citric acid 1-hydrate,

43.73 g (17.85 pphm) of water,

0.7 g (0.29 pphm) of pentasodium diethylenetriaminepentaacetic acid,

14.78 g (0.06 pphm) of methylenebisacrylamide (1% in water),

4.9 g (0.02 pphm) of tetraallylammonium chloride (1% in water),

8 g (0.16 pphm) of sodium hypophosphite (5% in water), and

326.66 g (100 pphm) of 2-trimethylammoniumethyl methacrylate chloride(quaternized dimethylaminoethyl methacrylate) (TMAEMC, 75% in water).

An oil phase is prepared by mixing the following components:

8 g (2.45 pphm) of sorbitan trioleate (75% in dearomatized aliphatichydrocarbon [Exxsol D40]),

67.83 g (5.23 pphm) of a polymeric stabilizer: stearylmethacrylate-methacrylic acid copolymer (19% in dearomatized aliphatichydrocarbon [Exxsol D40]),

151.29 g (61.75 pphm) of 2-ethylhexyl stearate (Crodamol OS) and

60.17 g (24.56 pphm) of dearomatized aliphatic hydrocarbon [Exxsol D40].

The two phases are mixed in a ratio of 58.2 parts of aqueous phase to41.8 parts of oil phase with high shear, and a water-in-oil emulsion isthus prepared. The water-in-oil emulsion which forms is introduced intoa reactor equipped with nitrogen spray line, stirrer and thermometer.The emulsion is purged with nitrogen, which removes the oxygen, and isthen cooled to 20° C.

The polymerization is achieved by adding a redox pair composed of

10 g (0.04 pphm) of sodium metabisulfite (1% in dearomatized aliphatichydrocarbon [Exxsol D40]) and

10 g (0.04 pphm) of tert-butyl hydroperoxide (1% in dearomatizedaliphatic hydrocarbon [Exxsol D40]).

The redox pair is added stepwise such that there is a temperatureincrease of 2° C./min. Once the isotherm has been attained, a freeradical initiator (2,2′-azobis(2-methylbutyronitrile), CAS: 13472-08-7)is added in two steps (the 2nd step after 45 min) and the emulsion iskept at 85° C. for 75 minutes.

By means of vacuum distillation, water and low-boiling constituents ofthe oil phase (Exxsol D40) are removed.

2-ethylhexyl stearate (Crodamol OS) is added to the vacuum-distilledproduct, which achieves a solids content of 53.5%. Thereafter, 7% (basedon the total proportion by mass of this product) of a fatty alcoholalkoxylate [alcohol C6-C17(secondary) poly(3-6)ethoxylate: 97% secondaryalcohol ethoxylate+3% poly(ethylene oxide)], known as Tergitol™ 15-S-7(CAS No. 84133-50-6), are added to produce a thickener (dispersion) with50% polymer solids content. The ratio of activator to cationic polymeris thus 14.0:100 [% by weight/% by weight].

Comparative Example C2

Synthesis of a thickener/polymer proceeding from cationic monomerswithout associative monomer and chain transfer agent, but withcrosslinker and rising polymerization temperature.

The synthesis is performed as in C1, but with the difference that nosodium hypophosphite (5% in water) and no tetraallylammonium chloride(1% in water) are added, and the amount of water is increased by 12.9 gof water. The ratio of activator to cationic polymer is 14.0:100 [% byweight/% by weight].

Comparative Example C3

Synthesis of a thickener/polymer proceeding from cationic monomerswithout associative monomer, chain transfer agent and crosslinker atconstant polymerization temperature.

An aqueous phase of water-soluble components is prepared by mixing thefollowing components:

1.88 g (0.5 pphm) of citric acid 1-hydrate,

109.85 g (29.32 pphm) of water,

1.07 g (0.29 pphm) of pentasodium diethylenetriaminepentaacetic acid,

500.00 g (100 pphm) of 2-trimethylammoniumethyl methacrylate chloride(quaternized dimethylaminoethyl methacrylate) (TMAEMC 75% in water).

An oil phase is prepared by mixing the following components:

12.24 g (2.45 pphm) of sorbitan trioleate (75% in dearomatized aliphatichydrocarbon [Exxsol D40]),

103.83 g (5.22 pphm) of a polymeric stabilizer: stearylmethacrylate-methacrylic acid copolymer (19% in dearomatized aliphatichydrocarbon [Exxsol D40]),

231.57 g (61.75 pphm) of 2-ethylhexyl stearate (Crodamol OS), and

92.10 g (24.56 pphm) of dearomatized aliphatic hydrocarbon [Exxsol D40].

The two phases are mixed in a ratio of 58.2 parts of aqueous phase to41.8 parts of oil phase with high shear to produce a water-in-oilemulsion. The water-in-oil emulsion which forms is introduced into areactor equipped with nitrogen spray line, stirrer and thermometer. Theemulsion is purged with nitrogen, which removes the oxygen.

The polymerization is achieved by adding a redox pair consisting of

13 g (0.05 pphm) of sodium metabisulfite (1% in demineralized water) and

13 g (0.05 pphm) of tert-butyl hydroperoxide (1% in demineralizedwater).

The rate for the addition of the redox pair is 13 g in 2 hours, thetemperature being kept constant at 50° C. Thereafter, a free radicalinitiator (2,2′-azobis(2-methylbutyronitrile), CAS: 13472-08-7) is addedin two steps (the 2nd step after 45 min) and the emulsion is kept at 85°C. for 75 minutes.

By means of vacuum distillation, water and low-boiling constituents ofthe oil phase (Exxsol D40) are removed.

2-ethylhexyl stearate (Crodamol OS) is added to the vacuum-distilledproduct to achieve a solids content of 53.5%.

Thereafter, 7% (based on the total proportion by mass of this product)of a fatty alcohol alkoxylate [alcohol C6-C17(secondary)poly(3-6)ethoxylate: 97% secondary alcohol ethoxylate+3% poly(ethyleneoxide)], known as Tergitol™ 15-S-7 (CAS No. 84133-50-6), is added toprepare a thickener (dispersion) with polymer solids content 50%. Theratio of activator to cationic polymer is thus 14.0:100 [% by weight/%by weight].

Comparative Examples C4-C5

As C1, but with changes according to Table 1:

TABLE 1 Exam- TMAE MC ples (pphm) MBA TAAC NaHP Comment C4 50 0.00250.0025 0.001 50 pphm of acrylamide C5 100 0.18 0.06 0.02

The ratio of activator to cationic polymer in comparative examples C4and C5 is in each case 14.0:100 [% by weight/% by weight].

Example 1

Thickeners/polymers proceeding from cationic monomers with associativemonomer:

The examples which follow according to Table 2 are produced likecomparative example C3 with incorporation of the specified changes inthe monomer composition and in the temperature regime. The associativemonomer C16EO25MAc is introduced into the oil phase. The commercialproduct Plex 6954 O is used, which comprises 60% by weight ofassociative monomer and, as solvents, water and MAA in a ratio ofapprox. 1:1. The weight data in Table 2 are based on the amount ofassociative monomer without solvent. The ratio of activator to cationicpolymer in all examples according to Table 1 is in each case 14.0:100 [%by weight/% by weight]; unless stated otherwise, the particularthickeners (dispersion) have polymer solids content 50%.

TABLE 2 C16EO25 MAc TMAEMC Examples (pphm) (pphm) MBA TAAC NaHP Comment1.1 0.19 99.75 — — — 1.2 0.19 99.75 — — — Temperature regime as C1;polymer solids content 30%; amount of activator adjusted correspondingly1.3 0.19 99.75 — — — Temperature regime as C1, but +1° C./min 1.4 0.1999.75 — — 0.16 Temperature regime as C1 1.5 0.19 99.75 0.06 0.02 0.051.6 0.19 99.75 — — — Temperature regime as C1 1.7 0.38 74.50 25 pphm ofacrylamide 1.9 0.76 99.00 1.10 0.38 49.5 50 pphm of acrylamideGeneral Test Methods

Unless stated otherwise, the following general test methods are used inthe examples which follow:

Determination of Viscosity

With reference to the methods according to DIN 51550, DIN 53018, DIN53019, the Brookfield model DV II viscometer is used, unless statedotherwise within the following tables, at the speed of 10 revolutionsper minute with the specified spindle no. 2 to measure the viscositiesreported in mPas.

Determination of Shear Dilution

Measurement is effected in an ASC (automatic sample changer) rotaryrheometer from Antonpaar, with the CC27 cylinder geometry, a radius ofthe measurement body of 13.33 mm and a radius of the measurement cup of14.46 mm. The measurement temperature is 23° C. The samples are measuredat steady-state shear beginning at small shear, increasing (0.01s⁻¹-1000 s⁻¹) and decreasing again (1000 s⁻¹-0.01 s⁻¹).

Example 2

Thickeners/polymers proceeding from cationic monomers with associativemonomer, and influence of the amount of activator on the thickening ratein aqueous formulations:

Examples 2.1 to 2.5 listed in Table 3 are prepared in accordance withexample 1.5 from Table 2, except that the amount of activator addedafter the distillation is varied according to the activatorconcentration (A %) in the thickener specified in Table 3 (all figuresin % by weight based on the amount of cationic polymer in thethickener). All thickeners thus prepared (dispersion) have polymersolids content 50%. The thickeners are subsequently added to the waterwhile stirring. These resulting aqueous formulations comprise 1% byweight of thickener to 99% by weight of water, i.e. 0.5% by weight ofpolymer to 99.5% by weight of water. C means comparative example.

TABLE 3 Thickening rate (Brookfield visc. mPa * s) of the aqueousformulations Examples A % 1 min. 2 min. 3 min. 5 min. 10 min. 20 min. 40min. 1 H 2.1 2.0 20 20 24 28 36 248 4800 7370 (C) 2.2 6.0 20 24 28 1283640 8300 9630 10600 (C) 2.3 14.0 72 740 2600 6200 9100 11120 1222012440 2.4 20.0 9100 10000 11060 11880 12540 12540 12780 12780 2.5 34.013280 13200 13140 13060 12920 12900 12800 12800

Aqueous formulations based on thickeners with 6% activator (ex. 2.2)have only attained a viscosity in the lower three-digit mPas range after5 minutes. In contrast, the corresponding value for example 2.3 (14.0%activator) is already in the middle four-digit mPas range after 5minutes.

Example 3

Use of the thickeners/polymers in standard formulations of fabricsofteners

W1: Preparation of a Di(Hydrogenated Tallow)Dimethylammonium Chloride(DHTDMAC) Fabric Softener (Active Content 4%)

To 1890 g of deionized preheated water are slowly added, while stirring,111 g of DHTDMAC (Arquad® 2HT-75) melted at 50° C. The dispersion isstirred and heated to 50° C. while stirring constantly for 15 minutes.The mixture is cooled to 30° C. while stirring. The pH is adjusted to4.0 by adding citric acid solution. The fabric softener is homogenizedby stirring.

LV Brookfield Viscosity (22° C., 30 rpm)=90 mPa·s.

W3: Preparation of a Methyltris(Hydroxyethyl)Ammonium Ditallow FattyAcid Ester Methosulfate, Partly Hydrogenated, Fabric Softener (ActiveContent 5.5%)

The fabric softener has a pH of 2.7 and comprises 5.5% by weight ofmethyltris(hydroxyethyl)ammonium ditallow fatty acid ester methosulfate(partly hydrogenated) and 94.5% by weight of demineralized water.

Addition of the Thickener to Fabric Softener Formulations W1 to W3:

The thickeners according to example 1 (Table 2) and comparative examplesare added gradually at room temperature to the particular fabricsoftener formulation and stirred until the formulation has homogenized.

The Brookfield viscosity is measured one day after the preparation. Theresults are compiled in Table 4.

TABLE 4 Thickener performance and shear dilution in fabric softenersRheology of fabric softeners comprising thickeners/polymers proceedingfrom cationic monomers: Viscosity Viscosity Viscosity ViscosityThickener at at at at Example Thickener concentration 0.1 s⁻¹ 10 s⁻¹ 100s⁻¹ 1000 s⁻¹ No. Formulation No. (%) (mPa * s) (mPa * s) (mPa * s)(mPa * s) 3.1 W3 V1 0.5 27992 833 221 63 (C) 3.2 W3 1.5 0.5 65986 1599377 67 3.3 W3 V1 1.0 47051 1441 352 106 (C) 3.4 W3 V3 1.0 11062 901 21356 (C) 3.5 W3 1.7 1.0 58440 2579 470 104

In addition to the high thickening performance, the relative percentageshear dilution in the inventive thickeners is also much greater than inthe comparative examples without associative monomer (like 3.1, 3.3 and3.4).

Example 4

Use of the thickeners/polymers in standard formulations of acidicdetergents

R1: Preparation of an Acidic Detergent of the Following Composition:

pH=5.3;

12 g of C₁₃-C₁₅ oxo alcohol ethoxylate with 8 EO

4 g of C₁₃-C₁₅ oxo alcohol ethoxylate with 5 EO

2.5 g of ethylhexanol ethoxylate

81.5 g of demineralized water

R2: Preparation of an Acidic Detergent of the Following Composition:

pH=1.8;

10.3 g of C₁₃-C₁₅ oxo alcohol ethoxylate with 8 EO

3.4 g of C₁₃-C₁₅ oxo alcohol ethoxylate with 5 EO

2.2 g of ethylhexanol alkoxylate

8.6 g of citric acid

75.5 g of demineralized water

The particular thickeners are added to these standard formulations asdescribed above in example 3. The Brookfield viscosity is measured oneday after the preparation. The results are compiled in Table 5.

TABLE 5 Thickener performance in acidic detergents Rheology of acidicdetergents comprising thickeners/polymers proceeding from cationicmonomers: Thickener Viscosity Viscosity Viscosity Example Thickenerconcentration at 0.1 s⁻¹ at 10 s⁻¹ at 100 s⁻¹ No. Formulation No. (%)(mPa * s) (mPa * s) (mPa * s) 4.1 R1 V1 1 16408 1850 618 (C) 4.2 R1 1.51 140080 6100 1425 4.3 R1 V3 1 4620 810 232 (C) 4.4 R1 1.7 1 13124 1163301 4.5 R2 VI 1 7550 962 350 (C) 4.6 R2 V3 1 927 405 140 (C) 4.7 R2 1.51 20918 1775 593

In addition to the high thickening performance, the relative percentageshear dilution in the inventive thickeners is also much greater than inthe comparative examples without associative monomer (like 4.1).

Example 5

Use of the thickeners/polymers in aqueous formulations

The aqueous formulations are prepared as described above in example 2.The Brookfield viscosity is measured one day after the preparation. Theresults are compiled in Table 6.

TABLE 6 Rheology of thickeners/polymers proceeding from cationicmonomers in water Brook- Brook- Brook- Brook- field field field fieldThickener spindle 3 spindle 3 spindle 3 spindle 3 Example Thickenerconcentration (1 rpm)/ (10 rpm)/ (50 rpm)/ (100 rpm)/ No. FormulationNo. (%) mPas mPas mPas mPas 5.1 Water V2 1 120 20 36 42 (C) 5.2 Water1.2 1 480 300 182 145

Example 6

In Tables 7 and 8 below, the storage stability of the inventivethickeners (according to example 1) and corresponding fabric softenerformulations (according to example 3) is examined. It is found that theinventive thickeners are much more stable.

TABLE 7 Storage stability of thickeners/polymers proceeding fromcationic monomers: Imme- Precipitate Precipitate Precipitate diate after4 after 3 after 10 Exam- Thickener precip- days at weeks at weeks at pleNo. itate 40° C. 40° C. 40° C. 6.1 (C) V1 none distinct, distinct,distinct, redispersible redispersible redispersible 6.2 1.1 none nonenone none 6.3 1.2 none none none none 6.4 1.3 none none none none 6.51.4 none none none none 6.6 1.5 none none none none

TABLE 8 Storage stability of fabric softeners W1 comprisingthickeners/polymers proceeding from cationic monomers: Imme- PrecipitatePrecipitate Precipitate Cationic diate after 4 after 3 after 10 Exam-LDP precip- days at weeks at weeks at ple dispersion itate 40° C. 40° C.40° C. 6.7 (C) V1 none distinct, distinct, distinct, redispersibleredispersible redispersible 6.8 1.1 none none none none 6.9 1.2 nonenone none none 6.10 1.3 none none none none 6.11 1.4 none none none none6.12 1.5 none none none none

Example 7

Thickeners/polymers proceeding from cationic monomers with associativemonomer, and influence of the amount of activator on the thickening ratein fabric softener formulations:

Examples 2.1 to 2.5 in aqueous formulation described in Table 3 areperformed analogously according to example 3 in fabric softenerformulations with fabric softeners (W3) according to Table 9 as examples7.1-7.5: again, the activator concentration (A %) in the thickener isvaried, and the amount of activator added after the distillation isvaried in accordance with the activator concentration (A %) in thethickener specified in Table 9 (all figures in % by weight are based onthe amount of cationic polymer in the thickener). All thickeners thusprepared (dispersion) have polymer solids content 50%. These thickenersare added to the fabric softener W3 while stirring. The thickened fabricsoftener formulations obtained comprise 1% by weight of thickener to 99%by weight of fabric softener W3, i.e. 0.5% by weight of polymer to 99.5%by weight of fabric softener W3.

TABLE 9 Thickening rate (Brookfield visc. mPa * s at 10 rpm) Example A %1 min. 2 min. 3 min. 5 min. 10 min. 20 min. 40 min. 1 H 3 H 7.1 3.0 152244 368 644 1316 2376 3616 4930 9180 (C) 7.2 6.0 248 492 784 1400 24683336 4520 5020 7560 (C) 7.3 14.0 1900 2900 3680 4650 5200 5420 5600 57506280 7.4 20.0 2700 3572 3996 4600 4690 4650 4880 4820 5400 7.5 34.0 56005560 5480 5340 5200 4810 4810 4810 5000

Fabric softeners based on thickeners with an activator content of morethan 10% (ex. 7.3-7.5) have obtained about 75% of the final viscositywithin 5 minutes. Below this limit, this value is attainable only after40 minutes. The higher the activator concentration established, the morerapidly the final viscosity in the formulation is obtained.

Example 8

Influence of the amount of crosslinker on the solubility of the polymerspresent in the thickener (proceeding from cationic monomers):

The measurement of the soluble polymer components given in Table 10 iseffected according to the method of P. Schuck (‘Size-distributionanalysis of macromolecules by sedimentation velocity ultracentrifugationand Lamm equation modeling’, Biophysical Journal 78, (3) (2000),1606-1619.).

TABLE 10 Determination of the solubility of the TMAEMC copolymerspresent in the thickener by means of an analytical ultracentrifuge (AUC)Soluble TMAEMC copolymer in thickener (dispersion) Examples Polymer (%based on overall polymer) 8.1 (C) V1 24 8.2 (C) V5 <1 8.3 1.6 100 8.41.9 100 8.5 (C) V4 22 8.6 1.10 83

The TMAEMC copolymers which have been prepared with 800 pphm or more ofcrosslinker comprise less than 24% soluble components. The TMAEMCcopolymers which have been prepared without crosslinker and in somecases with less than 1 pphm of associative monomers comprise more than99% soluble components. Acrylamide as a comonomer in TMAEMC copolymersreduces the solubility of the copolymer.

The invention claimed is:
 1. A thickener comprising i) at least onecationic polymer preparable by polymerization of a) at least onewater-soluble ethylenically unsaturated monomer comprising at least onecationic monomer, optionally at least one anionic monomer or optionallyat least one nonionic monomer, b) at least one ethylenically unsaturatedassociative monomer, c) optionally at least one crosslinker, d)optionally at least one chain transfer agent, ii) at least oneactivator, where the ratio of activator to cationic polymer is 10.5:100to 50:100 [% by weight/% by weight]; wherein the at least one cationicmonomer according to component a) in the cationic polymer is selectedfrom a compound of the formula (II)

where R₁ is H or C₁-C₄-alkyl, R₂ is H or methyl, R₃ is C₁-C₄-alkylene,R₄, R₅ and R₆ are each independently H or C₁-C₃₀-alkyl, X is —O— or —NH—and Y is Cl; Br; I; hydrogensulfate or methosulfate; wherein thenonionic monomer according to component a) in the cationic polymer isselected from N-vinylpyrrolidone, N-vinylimidazole or a compound of theformula (III)

where R₇ is H or C₁-C₄-alkyl, R₈ is H or methyl, and R₉ and R₁₀ are eachindependently H or C₁-C₃₀-alkyl; wherein the at least one ethylenicallyunsaturated associative monomer according to component b) in thecationic polymer is selected from a compound of the formula (I)R—O—(CH₂—CHR′—O)_(n)—CO—CR″═CH₂  (I) where R is C₆-C₅₀-alkyl, R′ is H orC₁-C₄-alkyl, R″ is H or methyl, n is an integer from 0 to 100; whereinthe crosslinker (component c)) in the cationic polymer is selected fromdivinylbenzene; tetraallylammonium chloride; allyl acrylates; allylmethacrylates; diacrylates and dimethacrylates of glycols orpolyglycols; butadiene; 1,7-octadiene, allylacrylamides orallylmethacrylamides; bisacrylamidoacetic acid;N,N′-methylenebisacrylamide, or polyol polyallyl ethers; polyallylsucrose or pentaerythritol triallyl ether; wherein the chain transferagent (component d) in the cationic polymer is selected from the groupconsisting of mercaptans, lactic acid, formic acid, isopropanol,hypophosphites, and combinations thereof; and wherein the activator isselected from the group consisting of fatty alcohol alcoxylates, alkylglycosides, alkyl carboxylates, alkylbenzenesulfonates, secondaryalkanesulfonates, fatty alcohol sulfates, and combinations thereof. 2.The thickener according to claim 1, wherein component a) in the cationicpolymer comprises 30 to 99.5% by weight of at least one cationic monomerand 0.5 to 70% by weight of at least one nonionic monomer.
 3. Thethickener according to claim 1, wherein, in the cationic monomer of theformula (II), i) R₁ and R₂ are each H or ii) R₁ is H and R₂ is CH₃. 4.The thickener according to claim 1, wherein the activator is selectedfrom fatty alcohol alcoxylates.
 5. The thickener according to claim 1,wherein a mixture of at least two activators is used, at least oneactivator having an HLB (hydrophilic-lipophilic balance) value of >12 to20 and at least one activator an HLB value of 1 to
 12. 6. The thickeneraccording to claim 1, which is present in a dispersion comprising an oilphase, wherein the cationic polymer is present dispersed in the oilphase.
 7. The thickener according to claim 6, wherein the dispersion isan inverse dispersion, water-in-oil dispersion, or a dispersed anhydrouscationic polymer in oil.
 8. The thickener according to claim 1, whereinmore than 25% by weight, based on the total weight of the cationicpolymer, of the cationic polymer is soluble in water.
 9. A process forpreparing a thickener according to claim 1, which comprises obtainingthe cationic polymer by an emulsion polymerization.
 10. The processaccording to claim 9, wherein the cationic polymer is obtained by aninverse emulsion polymerization.
 11. The process according to claim 10,wherein the inverse emulsion polymerization is followed and theactivator addition is preceded by distillative removal of at least aportion of water and at least a portion of the low-boiling constituentsof the oil phase.
 12. The process according to claim 11, which iscarried out by means of LDP (liquid dispersion polymer) technology. 13.The process according to claim 10, wherein component b) is added to theoil phase in the inverse emulsion polymerization.
 14. The processaccording to claim 10, wherein the temperature is kept constant or risesduring the inverse emulsion polymerization.
 15. The process according toclaim 10, wherein the temperature is kept constant during the inverseemulsion polymerization and is at least 40° C.
 16. Asurfactant-containing acidic formulation comprising at least onethickener according to claim 1, the pH of the formulation being 1 to <7.17. The surfactant-containing acidic formulation according to claim 16to be used in hair cosmetics, in hair styling, as a shampoo, as asoftener, as a conditioner, as a skin cream, as a shower gel, as afabric softener for laundry, or as an acidic detergent.
 18. Asurfactant-containing alkaline formulation comprising at least onethickener according to claim 1, the pH of the formulation being 7 to 13.19. The surfactant-containing alkaline formulation according to claim 18to be used as a liquid washing composition or as a machine or manualdishwashing detergent.
 20. The thickener according to claim 1 to be usedas a viscosity modifier, for optimization of shear dilution, as athickening agent, for stabilization of suspended constituents having asize in the range from nanometers to millimeters or insurfactant-containing acidic or alkaline formulations.
 21. The thickeneraccording to claim 1, wherein the ratio of activator to cationic polymeris 11.5:100 to 50:100[% by weight/% by weight].
 22. The thickeneraccording to claim 1, wherein the ratio of activator to cationic polymeris 14.0:100 to 50:100 [% by weight/% by weight].
 23. The thickeneraccording to claim 1, wherein in formula (II) R₁ is H; in formula (I) Ris C₈-C₃₀-alkyl, R′ is H, and n is an integer from 3 to 50; and whereinthe activator is selected from fatty alcohol alcoxylates.
 24. Thethickener according to claim 1 wherein the crosslinker (component c)) inthe cationic polymer is selected from the group consisting ofmethylene-bis-acrylamide and tetraallyl-ammonium chloride.
 25. Thethickener according to claim 17 wherein the crosslinker (component c))in the cationic polymer is selected from the group consisting ofmethylene-bis-acrylamide and tetraallyl-ammonium chloride.
 26. Thethickener according to claim 1, wherein the chain transfer reagent issodium hypophosphite.
 27. The thickener according to claim 17, whereinthe chain transfer reagent is sodium hypophosphite.
 28. Thesurfactant-containing acidic formulation according to claim 17, whereinthe ratio of activator to cationic polymer is 11.5:100 to 50:100[% byweight/% by weight].
 29. The surfactant-containing acidic formulationaccording to claim 17, wherein the ratio of activator to cationicpolymer is 14.0:100 to 50:100 [% by weight/% by weight].